How Much Brix Equals Percentage of Alcohol?

I have asked my friend Greg Perrucci to comment on the obvious and glaring differences in formulas to determine anticipated Alcohol from measuring Brix.

What prompted this was me reading that a winemaker who started at 25-26 Brix thought he was going to end up with alcohol close to 13%. My initial thought was he was using The latest Daniel Pambianchi book formula. Greg commented that his alcohol level would closer to 15% depending on yeast and other factors. So what gives? I figured I’d ask Greg to respond.

Greg Perrucci

Take a look at this Brix chart I’ve compiled over the years. The notes are not very good but there are 5 different ways to do it. The last one simply averages them all out. What I have found is that all yeast are slightly different in their ability to convert sugar to alcohol and every juice is different in actual sugar content compared to gravity.

go to the calculation section, then pick the article section, then pick the hydrometer/suagr/alcohol conversion piece. (sorry I couldnt get the direct link, for some reason it doesnt allow you to copy a link within a topic. If anyone can show me how to do this it would be appreciated.)

It goes through all the conversions and the formulas. According to, I believe it is Emile Peynaud, the temperature of the wine during fermentation will affect how much sugar is converted to alcohol. At higher fermenting temperatures you can blow off some alcohol. Also closed fermentors versus the open fermentors (used by most of us) can be a factor. Open fermentors produce less alcohol and closed will produce more.

Well that is a common practice when alcohol levels will inhibit mlf , temps are raised into the 90s. to blow off C2H5OH But I think the question remains should a winemaker with 25-26 brix really believe he is going to end up with anything less that 14.5 I don’t care what formula you use or even account for minor differences in yeast used or specific gravity.
What say you ? I think Daniel has really clouded the issue for new winemakers. Of course if you said that in the other forum you would get banned for a year. Bring out the Dart board guys.

I agree Dan’s numbers just don’t seem right to me. I think we discussed this not to long ago. I like his book as I think it is a good reference and makes a nice addition to anyones winemaking library.

When his new revised and updated book came out, I decided to get it. That is when I noticed his brix conversion charts and thought that cant’t be right. I would love to have dan explain those charts and how he came up with those numbers. Most charts I have read are not consistent with his charts.

Ah! The frustrations of Brix measurements; it’s right up there with SO2. Yes, my tables are different from SOME books. You’ll be hard-pressed to find two books with the same tables from a collection of several dozens of winemaking books – professional, academic, and home winemaking.

I’ll give you two perspectives: 1) practical, and 2) academic/theoretical. I’ll start with #1 because that’s what I recommend. Sorry for the lengthy answer, but you’ll appreciate the explanations.

#1
The reasons why we care about Brix is i) to ensure we harvest when grapes are ripened to a desired concentration, and ii) that the potential alcohol (PA) is in our desired range. As a commercial winery operator, I look at Brix to HELP with a decision on when to harvest though we look at phenolic ripeness and flavors – that’s key. We almost never consider PA since that can be easily adjustment up in the cellar.

And with Brix, we simply use our hydrometer to make those decisions. The hydrometer is a tool to GUIDE us; it’s most inaccurate, particularly the cheaper models – there are precision hydrometers but they are really not worth it for our purpose) – because of the many, many dissolved solids in juice that will affect sugar readings. It’s a really rough estimate. And whether the reading is 23.5 instead of 23.4, over even 23.0, doesn’t matter.

Since that’s the tool we use, stick to it to guide your winemaking and sugar additions.

PA is just a rough estimate and that’s part of the reason why we, commercial wineries, are allowed as much as +/-1.5% on the alcohol declaration on the label. So you really need not lose sleep over Brix. Just concern yourself with ripeness.

#2
Based on what I said in #1, many people want to know the sort of “real” Brix in juice – not the measured value knowing that it’s just an estimate. My table is based on the calculation PA = (Brix x 0.55) – 0.63, and this is a closer approximation to what’s in the juice and why I choose this as the basis of my table.

So a Brix of 24.8 would give a PA of 13.0% alc/vol. Some people even simplify this formula by dropping the subtraction so they can do a quick, mental calculation, i.e. 24.8 Brix gives 13.6%. Some simplify further by simply dividing by 2, i.e. 24.8 B gives 12.4%.

Daniel, first of all thank you for taking the time to answer my question. It is very much appreciated. I think I understand your reasoning. You expect a certain percentage of non- sugar solids in the must or sample, that effect, or most importantly, falsely increase the brix reading. You are simply trying to compensate for those non-sugar solids to get a more accurate reading.

Thank you for taking the time to respond to my question. I look forward to hearing from you again on this site.

Daniel,
Thank you for your comments.
I am a newbie to amateur winemaking. At this time I am not knowledgeable enough to make any comments about the art of winemaking, but since joining the Westchester Amateur Winemakers I’ve learned so much from a group of guys that are truly passionate about winemaking. I just racked my first season of wine and it seems like I’m ready to give birth. Gene, my teacher and our leader, is a tough taskmaster but one of the best.
Thanks again for sharing your knowledge

Thanks for the brix input. Welcome to the blog! I appreciate your simplifying the calculation by just saying divide by 2. That works for me and I agree the alcohol is easy enough to adjust if you need to. I was not aware of the leway regarding levels on labels. Thanks again!

Gene, I would like you to comment on your personal experiences using the centrifuge. Is it that much better than good old fashioned settling? If so, did you every do any kind of comparison that you could share?

I just dont believe the solids in a sample, after a reasonable period of settling, let us say 24 hours, could have a significant amount of non-sugar solids that would affect the brix reading. What is signifcant? I think anything more than 1/2 brix.

Well using the centrifuge initially made things faster and at the end of the day I would say that generally brix dropped by about 1 . So If I saw 24.5 raw I figured I was in the 23.5 for sure -23.9 highest posssible settled juice range. That is why the centrifuge stayed on the shelf. 25.5? Bring it on! NO problem for me. My latest 2007 Silver Medal Grenache. (Joey’s demise) was at 26.5. raw Balls to the wall no watering back. Result Perfectly balanced that in fact a real fooler. So balanced in acid and tannin that the alcohol is masked completely. Probably the most amazing wine I have ever made from that standpoint. Makes me want to make a quality Grenache next year. I hope Frank Musto is reading this.

The O7 Medal Silver Grenache. All Bachelors would want a case for the right occasion. Only 2 cases left available only on an emergency level basis. For me, I think Daniel’s formula puts the Yeast Manufacturer’s specifications closer to the test of the published limits.. But when serving your wine and you hear this wine is STRONG! my response , ” yea I know but I don’t drink Franzia in a box either”. My advice,buddy …. Drink less of it ….More for me and AL! ,Ernie, and Mario!

Somehow and in some unexplained way it always gets back to knowing the grapes you make wine with. And then judging PH, TA, and Alcohol. In a more experienced way. Another level to seek for me.

And in the old days when the Grandpa made wine and it was like mud (allicante at least 50%) but it was STRONG.
and do you really believe Grandpa ever fermented over 23 not using dreaded yeast, that maybe his wine was really not that strong at all? So what was it? Malic Acid, volatile acids, residual sugar. It wasn’t dry and had alcohol, that’s for sure.

But Daniel , no matter what, I am not giving up my laboratory calibrated standard hydrometer for nobody. I like to see where I am at and where I’m going. I hope you will become part of this blog. Thanks Gene

Thanks Daniel for the info! and welcome! Like the “Barbarian” I too did not know about the discrepancy in alcohol declaration.
Just saw a show with one of the contributing winemakers–Greg Perrucci. “Uncorked” Wine Made Simple with Ted Allen.They featured Paso
Robles,and how well Rhone varietals and Zin are grown there.They call it the next Napa.Anyway, Greg was part of a group to decide who would be the next “Zin Blend Master”…Ever get the job? Thanks very much Greg for contributing your expertise!…Anyone interested should check out the show.They go to a different wine region each week.

A while ago, I found is a formula that calculates Alcohol By Volume stated as a percent (%ABV)using Originating Specific Gravity (OG)and Terminating Specific Gravity (TG). It is: %ABV = 1000(OG – TG) / 7.4 or in English: Subtract the ending specific gravity from the beginning specific gravity. Multiply that difference by 1000 and divide that product by 7.4. The resulting quotient is equal to the Percent Alcohol By Volume.
On most triple scale hydrometers, the brix and the specific gravity of the liquid can both be read when testing the liquid. I don’t know what the conversion formula is for brix to specific gravity – I assume that it’s something like converting Farenheidt to Celcius since the zero points are different.
So if you had an OG of 1.0918 (22 brix) and a TG of .987 (-3 brix) the above formula would yield 14.162 %ABV or 28.3 proof. Realizing that different juices include elements in suspension (the stuff that adds to the lees) that affect the specific gravity, not all of it can be credited to sugar and therefore not all can be counted on to produce alcohol, what credence can be given to the above formula?